For a project of mine I have implemented the ID/IDREF XML pattern inside one of mine Web Services. When I created with JDeveloper a Web Service from it everything looked fine, no errors or what soever. I could receive this pattern inside my request messages without any problems. After I filled in the same String inside the IDREF as I did in ID the only response I get is a HTTP 200 without any body. For getting more information about the problem I used a custom SchemaValidationHandler inside my Web Service implementation.
On the 22nd of july, patchset 184.108.40.206 for Oracle 12c database was made generally available for Linux x86-64 and Solaris. This patchset includes the eagerly awaited In-memory option which promises an application transparent performance boost by using column-format data storage in memory.